OSMOTIC DEHYDRATION OF PAPAYA WITH CORN SYRUP SOLIDS

The water activity (a(w)) lowering capacity of four corn syrup solids (CSS) with nominal dextrose equivalent (DE) values of 10, 20, 30, and 40, and the osmotic concentration kinetics of papaya with solutions (50% w/w) of these solutes were studied. Apparent molecular weights (MW(a)) were calculated and the a(w) lowering capacity was characterized for each solute with Norrish's equation calculating a specific constant (K). The a(w) lowering capacity increased as the DE value increased. Logarithmic relationships were found between the MW(a) and the DE value and between K and DE (r greater than or equal to 0.993). The predicted a(w) values using the MW(a) and K of each CSS were in good agreement (average root mean square deviation less than or equal to 0.002) with the experimental data. Osmotic concentration was evaluated in terms of water loss (WL), loss of weight (LW) and solid gain (SG). The final values of SG increased and WL and LW decreased as the DE decreased. SG, WL and LW varied from 7.3 to 21.1%; 76.1 to 49.1%; and 72.0 to 28.0%, respectively for the CSS of 10 and 40 DE.